Ultrasonic speedsuhave been measured in [2-{2-(2-methoxyethoxy)ethoxy}ethanol+di-n-butylether], [2-{2-(2-ethoxyethoxy)ethoxy}ethanol+di-n-butylether], and [2-{2-(2-butoxyethoxy)ethoxy}ethanol+di-n-butylether] systems across the entire composition ranges, at the temperature 298.15 K, using a sing-around technique, at a frequency of 4 MHz. The values have been combined with those of the excess molar volumes to obtain estimates of the productK S, m of the molar volume and the isentropic compressibility κ S , and the excess valuesK S, m E were also calculated. The deviationu D of the ultrasonic speeds from their values in an ideal mixture were also evaluated for all measured values ofx. These values are compared with the mixing function δucalculated in the paper. The behaviour ofu,u D , andK S, m E with composition and the number of carbon atoms in the aliphatic chain of the alkoxyethanol is discussed.